The FMT-Dc series turbine meter is a unique meter, designed to perform on the highest level of accuracy. The meters comply with all international standards and are approved for custody transfer.
The actual flow sensor, TWO cartridges which are exchangable with conventional cartridges used in other turbine meter series, can monitor all kinds of flow effects and monitor the results if connected to flow computer devices. Since these flow computer can analyze any effect, the FMT-Dc is also able to monitor itself and detect any kinds of failures. For example bearing failures, blade failures of dirt in the meter.
When in use, the two independent turbine wheels are not subjected simultaneously to the same flow effects. This results in minimal differences between the two turbine wheels, which are being detected and diagnosed by the flow computer in a split second. This technique allows for a significant reduction of the uncertainty margin. Also, it opens new possibilities for the future, e.g. remote calibration could be a next step in successfully reducing the measurement uncertainty.
In order to fully exploit the possibilities of two turbine wheels, it has to be established that both turbine wheels operate independently and that occurring influences do not have the same effect at the same time on both turbine wheels.
Principle
The operation of the FMT series of turbine meter is based on the measurement of the velocity of gas. The flowing gas is accelerated and conditioned by the integrated multi stage flow conditioner. The multi stage flow conditioner prepares the gas flow profile by removing undesirable swirl and asymmetry before the gas flows over the freely rotating turbine wheel.
The dynamic forces of the flowing gas cause the rotor to rotate. The turbine wheel is mounted on the main shaft, with high-precision, low-friction ball bearings.
The turbine wheel has helical blades that have a known angle relative to the gas flow. The gas flow drives the turbine wheel at an angular velocity, which is proportional with the gas velocity. Using a gearing mechanism, the rotating turbine wheel drives the mechanical counter.
Applications
The standard FMT-Lx turbine meter is suitable for custody transfer gas measurement of all non-corrosive gases such as natural gas, propane, butane, air, nitrogen, hydrogen, etc. for low and high operating pressures. The special construction of the FMT-Dc enables to meet the performance of the FMT-Lx, but can provide twice the amount of information. The FMT-Dc can be modified to perform as a master meter or transfer master meter.